1. Technical Field
The present invention relates to a switching system, and more particularly, to a signaling test apparatus for testing a trunk register transmitting/receiving signaling, a subscriber service signal tone, a subscriber dual tone multi-frequency (DTMF) transmitting/receiving signaling, and a continuity check test (CCT) transmitting/receiving signaling in a switching system.
2. Related Art
Modern communication switching systems require that the communication lines and trunks connecting a central office system to subscriber stations and other offices be maintained at a high performance level. Therefore, it is necessary to provide means to accurately test transmission characteristics of the communication lines and trunks. Testing apparatus must be provided to accurately and conveniently measure signal transmission of the switching system. Examples of conventional testing apparatus are disclosed in U.S. Pat. No. 4,247,742 for Trunk Test Circuit issued to Thelen, U.S. Pat. No. 4,551,585 for Arrangement For Facilitating External Loop Analysis Testing For A Digital Switching System issued to Daniels et al., U.S. Pat. No. 4,794,632 for Telephone Trunk Line Testing Circuitry issued to Burton et al., and U.S. Pat. No. 5,111,497 for Alarm And Test System For A Digital Added Main Line issued to Bliven et al.
Contemporary testing apparatus generally measures only the frequency, level and cadence of a pulse code modulation (PCM) signal received at a PCM highway by means of a signal spectrum analysis equipment. Typically, the testing apparatus is connected to the highway during a test and measures the frequency, level and cadence of the PCM signal by selecting the channel only by the changeover of a manual switch without controlling a processor. Therefore, a trunk register signaling transmitting/receiving function, a dual tone multi-frequency (DTMF) transmitting/receiving function and a continuity check tone (CCT) signaling transmitting/receiving function cannot be accomplished. Moreover, I have noted that each signaling test item in the switching system requires an installation of a separate equipment, and as a result, it is difficult to secure expensive equipments for the test.